- The brainwave-connected device is able to grab objects that the user wants.
- The experiment has worked with two patients, a man and a woman who both lost the use of their limbs and their voice as a result of a stroke.
- The technology gives hope to millions of patients who have become paralyzed.
Scientists have invented a device that allows paralyzed patients to control a robot arm directly from their brains, bypassing their damaged central nervous systems.
This brainwave-connected device can grab objects that the user wants. The system uses baby aspirin-sized electrodes implanted directly into the primary motor cortex, the part of the brain that controls movement. Signals are routed through a tiny box in the scalp, which is connected by wire to a refrigerator-sized computer. The computer translates the brain movement patterns into an algorithm that transmits directly to the robot arm.
"The ultimate goal is to develop neural technologies to restore mobility specifically for people with no control of their arms or hands," said Leigh Hochberg, a neurologist at the Department of Veterans Affairs in Providence, R.I., who also has appointments at Massachusetts General Hospital, Brown University and Harvard University. "We're hoping to provide technology directly from brain signals back to commands that control assisted devices or limbs."
Hochberg and John Donoghue, director of the Brain Institute at Brown, had previously collaborated on the "BrainGate" project that produced the 2006 study showing how a patient could control a computer cursor using a brain-to-computer neural interface.
Their latest study, which appears in today's issue of Nature, goes a step further, developing a separate neural pathway to deliver messages from the brain to an arm, in this case an artificial one.
Hochberg said the experiment has worked with two patients, a man and a woman who both lost the use of their limbs and their voices as a result of a stroke.
Both patients moved the robot arm to grab foam balls. The woman picked up a metal coffee container and drank through a straw for the first time since she was injured 15 years earlier.
"The smile on her face was something I and our research team will never forget," Hochberg said.
The researchers cautioned that the efforts with the two patients only worked successfully about two-thirds of the time, and are not as fast or accurate as a human arm. But the experiment gives hope to millions of patients who have become paralyzed as the result of stroke or other physical trauma.
The next step is to rig the BrainGate system to a wearable prosthetic limb and after that, perhaps to the muscles in the paralyzed limbs themselves. The researchers compared the development of their project to the years of engineering and neuroscience used to develop cardiac pacemakers and deep brain stimulators that are now used to help Parkinson's disease patients. At first these devices were experimental and expensive, but are now common and affordable.
"There's no doubt that for this device to be successful, it has to reach people who would benefit and it will have to be affordable," Hochberg said."Affordable means that it's in a range that can be acquired privately or reimbursable by insurance."